INDIRECT PLANETARY CAPTURE VIA PERIODIC ORBIT ABOUT LIBRATION POINTS

Transcription

1 6 th International Conference on Astrodynamics Tools and Technique (ICATT) INDIRECT PLANETARY CAPTURE VIA PERIODIC ORBIT LI Xiangyu, Qiao Dong, Cui Pingyuan Beijing Institute of Technology Institute of Deep Space Exploration Technology 1 March 2016

2 Contents I. Introduction II. Concept of Indirect Planetary Capture III. Orbit Selection for Periodic Orbit IV. Simulation and Comparisons V. Conclusion 2

3 I. Introduction Planetary Capture A key process in planet exploration mission Interplanetary Trajectory Planetary Capture Mission Orbits Plays an important role in the trajectory design Fuel Consumption Capture Trajectory Design Flight System Design Interplanetary Trajectory Design Midcourse Correction 3

4 I. Introduction Current Capture Strategy Direct Capture Single impulsive maneuver at periapsis Easy to design Aerocapture v Take advantage of the aerodynamic force to reduce the velocity Precise guidance and control Fuel Saving Protection for high heat rate and overload Ballistic Capture Exploits the gravitational force of planets to capture a spacecraft Low energy Capture r p v Long transfer time Multi capture opportunities Fall when v is high From Belbruno and Miller

5 I. Introduction Circular Restricted Three body Problem (CRTBP) Libration(Lagrange) Points x Periodic orbits x 2y x rs Stable/Unstable Manifolds (1 ) y Space observation Low energy transfer Communication relay (1 )( ) ( x1 ) r y y 2x y 3 3 rs rm (1 ) z z z 3 3 rs rm 3 3 m Capture to periodic orbit Nakamiya and Scheeres (2008,2010) Wang (2014) Planetary Capture

6 II. Concept of Indirect Planetary Capture Concept Use periodic orbit as a park orbit Connect with interplanetary trajectory by stable manifolds Connect with mission orbit by unstable manifolds Interplanetary Trajectory Periapsis maneuver Stable manifold Periodic orbit about libration points Small perturbation Unstable manifold Periapsis maneuver Mission orbit 6

7 II. Concept of Indirect Planetary Capture Process Three impulsive maneuver First periapsis maneuver v1 v Perturbation to generate unstable manifolds v 2 Initial guess and correction Second Periapsis maneuver v a e 3, Process Three impulsive maneuver First periapsis maneuver Perturbation to generate unstable manifolds Second Periapsis maneuver 7

8 II. Concept of Indirect Planetary Capture Maneuver Three impulsive maneuver First periapsis maneuver v1 v Perturbation to generate unstable manifolds v 2 Initial guess and correction Second Periapsis maneuver v a e 3, Design Construct the periodic parking orbit Generate proper unstable manifolds same periapsis distance as mission orbit Generate proper stable manifolds for interplanetary design and midcourse correction 8

9 III. Orbit Selection for Periodic Orbit Orbit Selection Two criteria Energy constrain First maneuver v 1 as low as possible v1 vex vps vex ves v r r ps ps v es 2 r ps v1 1 rp rp rps 2 2 rp 2rp 2 2 2rp v v rp rp v v 0, v 0 r ps Periapsis of stable manifolds should close to the surface of Mars State constrain The periapsis distance of natural unstable manifolds should close to that of mission orbits 9

10 III. Orbit Selection for Periodic Orbit Sun-Mars System Planar Orbits Planar Lyapunov orbit L1 orbit from L2 orbit from Ay Ay to to Periapsis distance of stable manifolds 4 Ay Ay Critical amplitude A yc Ayc.10 Ayc

11 III. Orbit Selection for Periodic Orbit Planar Orbits Periapsis distance of unstable manifolds from 389 to Candidate parking orbits L1 orbit from Ay.10 L2 orbit from Ay

12 III. Orbit Selection for Periodic Orbit Planar Orbits Periapsis State Periapsis phase angle L1: ~ 0 L2: ~

13 III. Orbit Selection for Periodic Orbit Sun-Mars System Spatial Orbits Vertical Lyapunov orbit Large periapsis distance Infeasible Halo orbit L1 orbit from L2 orbit from to A to Periapsis distance of stable manifolds Az Az z Az 6.10 Critical amplitude A zc Azc Azc

14 III. Orbit Selection for Periodic Orbit Halo Orbits Periapsis distance of unstable manifolds from 389 to Candidate parking orbits L1 orbit from to Az A z L2 orbit from Az to A z

15 III. Orbit Selection for Periodic Orbit Halo Orbits Periapsis State Orbital Inclination Periapsis phase angle Periapsis Spatial angle i L1: L2: i 20 i 140 i 20 i 130 1

16 III. Orbit Selection for Periodic Orbit Halo Orbits Periapsis State Orbital Inclination Periapsis phase angle Periapsis Spatial angle i L1: L2: 10 ~ ~

17 III. Orbit Selection for Periodic Orbit Halo Orbits Periapsis State Orbital Inclination Periapsis phase angle Periapsis Spatial angle i 19 L1: L2:

18 IV. Simulation and Comparisons Direct capture 2 2 (1 e) vd v rp a(1 e) r r p p Indirect capture First impulsive maneuver 2 2 v1 v vps rps Third impulsive maneuver v v 3 rps 389 pu (1 e) r v v1 v2 v3 p Perturbation velocity v2 1 m / s Capture Time Ts T p Tu T Ts Tp Tu Stable manifold transfer time Parking time Unstable manifold transfer time 18

19 IV. Simulation and Comparisons Mission Orbit I 200 circular orbit Parking orbit L2 planar Lyapunov orbit Ay.710 v (/s) Direct Capture Indirect capture vd v vd (/s) v (/s) T (day) (/s) Low orbit capture: Cost the same velocity as direct capture Provides a chance to explore the space environment in the vicinity of Mars and Lagrange points without extra velocity increment Long transfer time 19

20 IV. Simulation and Comparisons Mission Orbit I 200 circular orbit Parking orbit L2 planar Lyapunov orbit Ay

21 IV. Simulation and Comparisons Mission Orbit II 800*60000 elliptic orbit Parking orbit L2 Halo orbit v Az (/s) Direct Capture Indirect capture vd v vd (/s) v (/s) T (day) (/s) Middle orbit capture: As the periapsis of mission orbit increases, the indirect capture requires less velocity than direct capture Save more fuel for higher excess velocity v 21

22 IV. Simulation and Comparisons Mission Orbit II 800*60000 elliptic orbit Parking orbit L2 Halo orbit Az

23 IV. Simulation and Comparisons Mission Orbit III circular orbit Parking orbit L1 Halo orbit v Az (/s) Direct Capture Indirect capture vd v vd (/s) v (/s) T (day) (/s) High orbit capture: Save more than 30% velocity Keep the same efficiency in high v 23

24 IV. Simulation and Comparisons Mission Orbit III circular orbit Parking orbit L1 Halo orbit Az

25 INDIRECT PLANETARY CAPTURE VIA PERIODIC ORBIT IV. Simulation and Comparisons Mission Orbit IV Elliptic orbit e 0.9 with different periapsis distances Parking orbit L1 Lyapunov orbit v 2. / s Cost is approximately constant regardless of the periapsis distance 2

26 V. Conclusion Indirect capture could save velocity increment than direct capture at the cost of long transfer time Shows better efficiency for high altitude and high v orbit insertion Extra scientific returns Increases transfer flexibility Reduce gravity loss 26

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